by the way i had GT 2 for PS one and its still better than any xbox racing game i wish they had GT for xbox it was so much fun

The problem with the GT series (still applies to GT4 imo) is that they don't make you feel connected at all. You can be driving 220mph+ and all the cars are rock steady. The tires all make one noise. You can't judge speed visually, or at least I can't. I dunno. Everything feels really distant.

The game really changes in terms of feel as the performance bracket goes up. They start you off with a simple, low-powered FWD/AWD car and soon enough you'll find yourself in high-powered RWD monsters.

To ease yourself in the game I suggest you leave your settings like this:
-Braking line on (Don't bother with the full line. You can also usually brake late after the line goes red.)
-ABS on
-DTC on
-DSC off
Transmission Manual (Auto only if you really don't know when to shift. If so just watch where the cpu shifts and where it keeps you in the rev range.)
-Difficulty easy/medium (I like medium, and easy can make it a pushover)
-Damage simulation
-Fuel/Tire wear simulation

Also, when you're looking to buy upgrades focus on the handling department. Weight reduction, tire composition, brakes, and suspension should be your top priorities. Upgrading your cams and valves is probably the best engine upgrade because it increases the rev limiter. The first thing I usually upgrade engine-wise is the exhaust, mainly because it just sounds better.

Follow the line and be smooth with your acceleration and braking and you should get the hang of things really fast.